Resin molded article and method for producing resin molded article

Abstract

An object of the present invention is to provide a technique by which, when producing a resin molded article using an insert member having low pressure resistance, molding can be easily performed, and deformation of the insert member can be suppressed. A method for producing a resin molded article of the present invention, the method includes the steps of disposing an insert member in a cavity of a mold; performing injection of molten resin into the cavity; terminating the injection on and after the molten resin reaches an overflow portion in the cavity and before the molten resin fills the overflow portion; and separating resin in the overflow portion.

The invention claimed is: 
     
       1. A method for producing a resin molded article, the method comprising the steps of:
 disposing an insert member in a cavity of a mold; 
 performing injection of molten resin into the cavity; 
 terminating the injection on and after the molten resin reaches an overflow portion in the cavity and before the molten resin fills the overflow portion; and 
 separating resin in the overflow portion, 
 wherein: 
 the insert member is one or more tubes, 
 no core bar is inserted into the one or more tubes, and 
 under compression load of 100 gf per 1 cm of a length of the one or more tubes by a pressure element, the one or more tubes have a height in a direction of compression of 7/10 or less of a height in the direction of compression prior to applying the compression load. 
 
     
     
       2. The method for producing a resin molded article according to  claim 1 , wherein a molding temperature is 100° C. or higher and 250° C. or lower. 
     
     
       3. The method for producing a resin molded article according to  claim 1 , wherein a pressure of the injection is 0.1 MPa or more and 50 MPa or less. 
     
     
       4. The method for producing a resin molded article according to  claim 1 , wherein a pressure applied onto the insert member after the injection is 5 MPa or less. 
     
     
       5. The method for producing a resin molded article according to  claim 1 , wherein a melt viscosity at 200° C. of the resin is 5 dPa·s or more and 5000 dPa·s or less. 
     
     
       6. The method for producing a resin molded article according to  claim 1 , wherein the resin is at least one hot-melt resin selected from a group consisting of a polyester-based hot-melt resin, polystyrene-based hot-melt resin, polyolefin-based hot-melt resin, polyurethane-based hot-melt resin, polyamide-based hot-melt resin, and reactive hot-melt resin. 
     
     
       7. The method for producing a resin molded article according to  claim 1 , wherein the resin is at least one thermosetting resin selected from a group consisting of a phenolic resin, unsaturated polyester resin, diallyl phthalate resin, and polyimide resin. 
     
     
       8. A resin molded article comprising one or more tubes and a sealed part in which at least part of the one or more tubes is sealed in resin,
 wherein, under compression load of 100 gf per 1 cm of a length of the one or more tubes by a pressure element, the one or more tubes have a height in a direction of compression of 7/10 or less of a height in the direction of compression prior to applying the compression load, and 
 a ratio of a minor diameter to a major diameter of the one or more tubes in the sealed part at a position 1 cm away from one end of the sealed part in an axial direction of the one or more tubes is smaller than a ratio of a minor diameter to a major diameter of the one or more tubes in an exposed part that is not sealed in the resin at a position 1 cm away from the one end. 
 
     
     
       9. The resin molded article according to  claim 8 , wherein a ratio of the minor diameter to the major diameter of the one or more tubes in the sealed part is 0.9 or more. 
     
     
       10. The resin molded article according to  claim 8 , wherein the one or more tubes in the sealed part have a minimum thickness of 0.05 mm or more and 0.5 mm or less. 
     
     
       11. The resin molded article according to  claim 8 , wherein the one or more tubes have a branched part, and the branched part is sealed in the resin. 
     
     
       12. The resin molded article according to  claim 8 , wherein the resin molded article is an injection molded article.